Shotgun Sight Installation Advice Wanted

rc

New member
Hi, I purchased a shortened shotgun barrel without a rib from ebay that had a boogerd hacksaw job. Barrel is about 20" so length is fine. I have squared the muzzle with my 5" disk sander and now I need to install a bead. I've picked up a centering V shaped jig at harbor freight for my drill press and ordered a Mossberg plain barrel front sight and 5-40 tap + majic tap fluid. I'm going to build a jig to hold everything steady in the drill press and got an automatic center punch to help keep the drill from walking around when I start drilling metal. The one thing I haven't lined up yet is the drill bit. What size hole should I make when my drill press is set up? Should I do this in two step or just drill the correct diameter hole the first time? I'd like to keep the bead as square to the action as possible so the gun points right. Hope to get some experienced advice. Good news is if I booger the job the first time I can still cut back a bit and retry. I do hope to do it right the first time.
 
A #38 number drill will give you a 75% thread so that is the drill to use. The nearest fractional drill is 7/64 but it only provides a 50% thread.
Are you planning on drilling through the barrel and then filing the screw flush on the inside of the barrel? You may find that you need to raise the bead to get the proper fit to align with your target. We had to put the bead on a 3/8" ramp to get my brothers shotgun to line up with the point of impact. His was cut to 18-1/8" and I rolled a full plus choke on it for him. It shoots well for him now.
 
Thank you.

I appreciate the correct drill # for correct thread engagement. I will see if I can find the right one locally since I didn't order it from midway. I will drill through and file down the inside with my dremel. How do you roll a choke? I would love to taper it down a bit from cylinder. Also, is there a standard 12 guage ramp? Not pointing correctly is a bit of a concern. Right now I can't even see the barrel with a good cheek weld.
 
rc,
I made a four roller clamp that was a bit like a pipe cutter without the cutter wheel. I rolled it and let it slide toward the front of the muzzle as I tightened it down. It went pretty quick but it did manage to break the small ball bearings I used. If I was going to make another one I think I would use bushings instead of bearings. I used a tapered shaft marked with tape to gage the amount of taper compared to another gun with a full choke. I stopped the process when it was a tad tighter than the full choke. Then we patterned the shotgun and adjusted the crown to shoot where my brother wanted it.

The ramp I used was an old ramp sight from a Thomson Contender. I had to match the fit to the barrel diameter and made a new bead with threads that were just long enough to not protrude into the bore. I know that "clip on" sights are made for shotguns and it would be a simple matter to use that with a locating hole and a screw to hold it in place. There are also extended beads that sit higher than the flush beads.
 
good information!

Thank you for your help. I am hoping the Mossberg plain barrel bead will be high enough for my Remington barrel without a ramp and it also has wrench flats to tighten it. I'm not sure of the difference between Mossberg and Remington receiver height. I went to sears today but no luck finding a #38 drill bit and I would have to special order a 12 pack. Will try another hardware store tomorrow.
 
rc,
You can get a whole set of number drills from Harbor Freight. If you don't use them a lot they will be fine. I have three different sets from different manufacturers but then I use numbered bits a lot.
 
I wanted cobalt

I ordered 2 for about $5. The better the drill cuts the less it will try and walk.
 
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